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Discussion Starter #1
Hey everyone, I just got my factory pro adjustable ignition rotor, and was wondering how much timing I can SAFELY run? I'm about 500 ft. above sea level in RI. The bike have yoshi slip ons, and a dynojet jet kit. I think I can get away with running 5*, but wanted to know what everyone else was running, and with what result.
Thanks
 

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I'm running the Factory Pro non-adjustable unit on the advice of Marc Salvisberg at Factory Pro. He didn't think I'd need much or any more then this for a sport touring machine on pump gas. It's set for 4degree's advanced as is. I've not done anything else to the motor (TiForce pipe sits in wait, Factory Pro Jet Kit sits in wait, that I got a couple years ago now, but some day...) and it seems to have more grunt, caution "Seat Dyno in use here", which means I'm full of shite of course. One thing to be sure of as you install it. Take the old trigger plate and over lay it onto the Factory Pro unit,..then make the stock timing marks in the new FP unit. This will enable you to do the factory service manual valve sim procedure and ensure you line up the timing marks as per Honda. My FP unit was devoid of any timimg marks, so I did this after the fact. Much easier to make the marks as you do the change out,..then your golden when valve clearance check time comes "around". Stock fuel requirements state "Regular- 86 octane (pump octane) as a min. I've never heard knock myself while riding,..but my buddy thought he heard knock once,...so I've moved up to mid grade in the fuel department, 87 or 89 ontane (note: this is pump octane,..Pump octane = research octane + motor octane /2 (divided by 2) = pump octane. The standard octane rating for most if not all of North America/ Canda is pump octane.


HTH.

Tony
 

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Discussion Starter #3
Thanks Tony. I always use 93 octane, or highest available rating anyways. But if figure with the high octane, and the fact I have the carbs jetted for more fuel, I can safely run the +5*, I figure, just to squeeze that little bit of performance out of it.
 

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I've always thought, in a general sense, that timing advance settings are a function of the cylinder compression ratio and what fuel is available or what fuel one wishes to run, which will control the onset of engine knock. The amount or method of fuel delivery or exhuast expulsion will, as I see it, have little to nothing to do with the effects of timing advance. For sure any rich or lean conditon will effect overall operation of the engine and therfore jetting/fuel metering needs to be correct. You need only set the timing to that which your fuel will allow and support without knock. Not to get into the "octane wars", but I maintain that if your running more octane then required for the motors state of tune you are in effect throwing your money away, be it only pennys per gallon for some. Here in Canada the cost savings can run upwards of 10 cents a liter to move to the next higher octane rated fuel, depending on the day of the week. There is I believe a male mind set that states "If more is better, then too much is just enough." So if a bit of octane is good then more must be better, yes perhaps if you wish to error on the side of knock safety. But to do so just because you can or wish is to simply waste money where it need not be spent. For a given state of tune the increased octane number does not net you an increase in power. If your pushing for max performance then fuel will, I should think, be one of the limiting factor in your set up.

I remember back in the day that upper advance setting in the hot rodded V-8's of the day worked well for the first start of the day, but as engine temps increased the hot start performance and starter motor performance became somewhat taxed if the motor could not be cooled down enough before the next start up. I don't know if the same might happen with the motorcycles or not. It may be wise to sneak up on your advance settings if you push above the 4 or 5 degree mark and see how things perform. A dyno run might be the only true way of seeing any performance (power) gains that the increased advance provides. It would also allow for exhaust gas analyzing that would indicate if your fuel metering is correct.

It will be interesting to see where you end up with our adjustable advancer. Please keep us posted.

Tony
 

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Discussion Starter #5
Well, after calling factory pro, to get an opinion about running 5* more timing, all they could tell me was that if i do it, I should listen for knock and if I loose top end, I added too much tming. Pretty much useless. I guess I'll just add the 5*, and see where I stand. I'd just hate to do it, and then have to go out and buy another $20 gasket to take out 1* of timing. But whatever happens, happens. I"ll keep you posted if I ever get some time to actually throw the timing rotor in, hopefully next weekend.
 

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Discussion Starter #6
Well, got around to doing the timing rotor today. I opted for advancing the timing 5 degrees...What a difference. No detonation, from what I can hear; and the bike is a lot more repsonsive throughout the RPM range. Great mod, highly recommended!
 

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Well, got around to doing the timing rotor today. I opted for advancing the timing 5 degrees...What a difference. No detonation, from what I can hear; and the bike is a lot more repsonsive throughout the RPM range. Great mod, highly recommended!
You will not know if it is a good mod until you pull the engine down. Signs of long term, slight detonation are cratering and fatigue fractures in the white metal surface of the big end shells, alignment of the ring end gaps and fracturing of the piston skirts. You will not hear detonation/pinging on an engine that is slightly too advanced but it will have long term effects. Paul :).
 

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Discussion Starter #8
TigerST was running 86 octane on a stock bike and didn't hear any ping/detonation, but his friend thought he heard something so he now runs 87 or 89 octane. I always run 93 octane, and i jetted the carbs too. I also talked to a local bike shop where the guy is pretty knowledgeable with blackbirds, and he said I should have no issues running 5*. I would like to get it on a dyno though, just to make sure everything is good.
 
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